1. Field of the Invention
This invention relates generally to a passenger vehicle occupant restraint system and, more particularly, to a vehicle occupant restraint system comprising an air bag module which permits deployment of an air bag cushion in an alternative direction.
2. Background Art
Passenger vehicle occupant restraint systems are well known. During an impact of sufficient magnitude, an inflator inflates an air bag cushion which breaks through notches on an air bag cover and inflates inside a vehicle to protect a vehicle occupant. However, under certain conditions the deployed air bag cushion may not perform optimally. In particular, if the occupant is out of position and too close to the passenger vehicle occupant restraint system, the force of the deployed air bag cushion may jolt the occupant and/or not provide optimal protection.
Vehicle occupant restraint systems have been provided with venting means to reduce the pressure of the air bag cushion during deployment to minimize potentially adverse effects due to an out-of-position occupant. While highly effective, the majority of the vented systems require complicated manufacturing and/or sensing systems and do not provide optimal protection when the vehicle occupant is out of position.
Accordingly, it is desirable to provide an occupant restraint system to protect out-of-position occupants in a simple and cost effective method.
It is an object of this invention to provide a vehicle occupant restraint system comprising an air bag module to protect out-of-position occupants which is not dependent on venting the air bag cushion and/or sensing means.
Accordingly, this invention provides a vehicle occupant restraint system comprising an air bag module which includes an air bag cushion having a folded condition and an inflated condition, an inflator to inflate the air bag cushion, and a cover enclosing the air bag cushion when it is in the folded condition and having a front wall facing the seated occupant and side walls. Under normal crash conditions, such as when the occupant is properly belted, the air bag cushion deploys through the front wall of the air bag cover substantially directly toward the occupant and provides protection to the occupant in a known manner.
However, when the occupant is out of position and is exerting a force against the front wall of the air bag cover sufficient to impede deployment of the cushion through the front wall, pressure builds within the cushion until weakened areas in the side walls of the air bag cover release or rupture to create openings in the cover, thereby providing a lateral deployment path for the inflating cushion. The air bag cushion then surrounds the vehicle occupant and reduces injury potential to the out-of-position vehicle occupant compared to a normally deployed air bag.